The Pollution Control Board official said that for the next few days, the air quality in Delhi will stay above the count of 350.

Commuters seen wearing face mask to avoid thick smog, as the air quality deteriorated sharply overnight leading to poor visibility conditions across the city, in New Delhi, India, on November 21, 2016. (HT File Photo)

Air quality in Delhi is set to worsen in the next few days because of weather conditions.

According to meteorological department forecast, easterly winds, blowing from Uttar Pradesh, will introduce moisture in the city’s air over the next few days and fog will start building from October 29.

“Wind from north-east, east and south-east will carry moisture to Delhi. Dispersal of pollutants will only happen during the day, in a six-hour window, between 11-5. This will ensure pollutants having local sources such as vehicular emission, road dust, smoke from garbage burning and so on remain at the ground level for longer hours,” Central Pollution Control Board member secretary A Sudhakar told Hindustan Times.

According to him, the sky has gradually started turning hazy and will remain visibly polluted over the next three to four days.

On Wednesday, Delhi had a “very poor” AQI at 344 while Ghaziabad had the worst air quality in the country of “severe” levels at 425. Bhiwadi 397, Gurgaon 318 and Noida 363 all were in the very poor levels.

According to the System of Air Quality and Weather Forecasting And Research, PM10 readings on Wednesday was 301µgm3 and is expected to touch 313µgm3 on Thursday, both in “poor” levels.

PM2.5 levels were at 175 µgm3 and expected to reach 182 µgm3 on Thursday, both in “very poor” levels.

The CPCB official said for the next few days, the AQI of Delhi will stay above 350.

“There has been little impact of the stubble burning in neighbouring Haryana and Punjab in the city’s air unlike previous years till now.

The westerly winds are not entering the city and preventing the entry of air-borne residue of stubble-burning. However, because of the moisture, pollution levels will get worse. This is just the beginning,” he said.

These weather conditions are similar to the post-Diwali period, when moisture coupled with easterly winds and burning of firecrackers, despite a ban on their sale, made the city air quality nosedive.

The Air Quality Index (AQI) of Delhi stood at 403 the day after Diwali, markedly better than 2016’s post-Diwali count of 445. However, it did not fare as well as the same period in 2015 — when the AQI count measured just 360.

The Supreme Court-mandated Environment Pollution (Prevention and Control) Authority has already enforced a raft of measures under the “very poor” and “severe” categories of the Graded Response Action Plan, including a ban on diesel generator sets with certain exemptions.